Something wrong, or something to ask. Either way, one real person reads this.
The App Store listing is not open yet. push4ai.com/install explains how to get it through TestFlight, Apple's own testing app, in the meantime.
Sign in, open the Agents tab, and create one - it gives you a key. Paste that key into push4ai.com/try and it walks you through every kind of push, live.
Signing in adds it automatically, no card needed. It is enough credit to try every kind of notification the app supports.
In the app, Account tab, Manage Account. It opens a page on push4ai.com for that one visit, no separate sign-in.
In the app: Account tab, the gear icon, Delete Account. It is immediate and cannot be undone. Full detail on the privacy page.
Read the privacy page - it says plainly what is collected, who else sees it, and how to remove all of it.